Average Relative Humidity in October at US Cities

The average humidity in October is listed here for the largest cities in the United States. The tables below give this month's daily averages along with morning and afternoon relative humidity levels.

Relative humidity measures the actual amount of moisture in the air as a percentage of the maximum amount of moisture the air can hold.

For each city, the Daily number gives the average of humidity readings taken every three hours throughout the day. Morning values are recorded between 4 and 6 am local standard time, when usually temperatures are coolest and humidity highest. Afternoon humidity percentages are readings taken between 3 and 5 pm local standard time, when normally the day's temperature peaks and relative humidity reaches its lowest point. All the figures are averages for the years 1961 to 1990.